Friday, July 31, 2009

I've just added support for Mic-E message bits. These are sent only in the Mic-E formatted packets, and I've been told it's quite easy to switch between the different messages in the Kenwood TM-D700 / TM-D710 rigs. I don't know how, since I don't own any of these rigs, and they're a bit expensive. If you're working for Kenwood, please consider sending me one for review and compatibility testing, there are over 130 000 potential APRS users visiting this site every month (absolute unique visitors according to Google Analytics). You can find my email address behind the 'complete profile' link on the right. Thank you. :)

The Mic-E status message is encoded in the packet using just a few bits, and can contain one of these 8 standard messages: Off duty, En route, In service, Returning, Committed, Special, Priority, Emergency. 7 custom messages (Custom 0 to Custom 6) are also defined.

The current message is shown on the info page of the sending station, and the info balloon of the current position on the real-time map. Old values of the message bits are currently not stored in the database.

Tuesday, July 21, 2009

This morning I upgraded the master database engine. The upgrade stopped data updates for a few minutes, but the site was viewable during the upgrade.

I also installed new aprs.fi software on the servers. The new version adds support for the APRS equivalent of the email / newsgroups x-no-archive header, "!x!", which can be placed in the beginning of the comment text of a position packet. It prohibits aprs.fi (and findu) from archiving the position packet in the database. This is quite an old feature in findu, and has not really been documented anywhere (except the APRSSIG archives).

The !x! string is different from using NOGATE or RFONLY in the digipeater path. NOGATE/RFONLY prohibit gating the packet to the APRS-IS completely. !x! does not forbid igates from gating the packet on the Internet, it just requests that the packet is not stored in databases for a long time.

Please note that not all igates or databases support these features. Amateur radio transmissions are defined to be in the public domain (by FCC rules in the US, and by respective legislation in most other countries, and I suppose, by international regulations). Anyone can receive them, and retransmit, publish or store them as they wish.

As Steve Dimse put it on the APRSSIG: "if you do not want your data appearing on the internet the only guaranteed way is not to transmit it!"

I also added a search button to message and raw packets browsing views, and fixed a bug in clickable callsign links in digipeater paths. And did a rather massive source code tree reorganisation, making it a bit more tree-like.

Wednesday, July 8, 2009

Today I upgraded the slave databases to a new major release of the database engine. I'd like to use some of the new features to increase the performance of the system.

The upgrade itself, and the necessary conversions, wouldn't have caused any outages, since I can tell my software to do queries on another database server while upgrading one (in fact, they will automatically fail over to another server if one is down). But, as usual, there was something I overlooked, and for a few minutes about 50% of the /info/ page requests failed and complained about problems with looking up nearby cities. I had to improve the stored procedures a bit to get them working on the new database engine version.

Please, drop a note in the blog comments, if you notice any other problems.

If you already have an account on aprs.fi for posting AIS data, and you don't have your login password (it's different from the AIS feeding password, and no, you didn't have one before since there was no such thing before today), try logging in with your email address and any bad password, and you'll get to the "forgot my password" path which lets you reset the password to a new one.

As usual, there are quite a few new strings to be translated. From now on, you'll have to sign up for an account and log in to access the translation tool. I hope you don't mind.

Sunday, July 5, 2009

It's been a bit quiet here for some time, since I've been working on some larger changes in the aprs.fi back-end system (and learning how to fly, crash and repair an RC airplane). I'm planning to install the changes on the production servers early on Tuesday or Wednesday morning (7th or 8th of July 2009, around 4:00 UTC). The outage shouldn't be a long one, if all goes well.

One of the visible changes is a new authentication and authorization layer, which is based on a conventional email address + password model with a team-based authorization system. It'll enable some new features and services later (once I get around to implementing those) - in the first phase it just lets you sign up for submitting AIS data without manual work on my part.

There's no need to worry, as a normal user viewing data on aprs.fi, you won't need to sign up for an account. Logging in is completely optional, and I won't encourage or beg everyone and their cat to sign up. In fact, the "login with your nickname to see the map" model will go away - you'll end up directly on the map page when you arrive on the site, and the "most usual" site entrance path will be easier and quicker than before.

I will be adding an "introductory" entrance page for first-time visitors later, so that there's a chance to let them know what this site is all about. But it'll only be shown once for each visitor.